Daz Bones can be exchanged for Miss Doublefinger, she boosts DEX ATK by 1.5x.

Ashura Zoro can be exchanged with Trafalgar Law for almost guaranteed DEX Orbs.

Overall Strategy:

Get up your Specials before get to Enel.

Tank his hits until you can turn delay him.
Burst out everything you have in 2-3 turns.

Stage 1: Stall as necessary and take around 2 hits from a mob and make sure that thunder kills the mob after that.

Stage 2: Kill the turtles as needed. It is fine if you take a hit here. but lightning will kill them after they attack once. So make sure you take only 1 hit from one of the turtle/mob if you cannot kill them.

Stage 3:

The mob should lock GP Usopp and Mr. 1 here.

Use the other units to kill the mobs with 1 cd on the play leave one of them (preferably QCK) alive so that he can lock your characters.

Try to kill the INT mob if he is at 1 cd as he locks all DEX units if you let him attack.

But even if he does, it is still possible to beat the stage.

Let a mob lock you one more time. Make sure that the lightning countdown is at its second turn here

Stage 4: Kill the mob who is at 1 cooldown (if any) and let the lightning take care of the rest.

Stage 5:

By this turn you should have stalled 19 turns safely.

After enels preemptive attack, turns stalled = 20

After this you should be able to tank 6 regular Enel hits minimum.

Tank more if possible for safety.

As soon as Enel shuffles orbs when you are at low health, use Usopp special.

By this time you should have done around 35-40% damage to enel

Use Mihawk Special after GP delay

Attack for 1-2 more turns normally

By this time both the Doflamingos should be charged

Use one Doffy special and get good orbs on the DEX characters.

Use Mr 1 special to boost attack for 2 turns

Hit your perfects and burst down as much as possible.

Use Ashura Zoro's special for some minial damage as well.

The boosted orb power from doffy and the power from Mr. 1's boosted attack should be enough to kill Enel after the second doflamingo boost

We wish you the best of luck and hope this helped you in your quest to obtain the terror of Skypiea and hope that you can max his special soon.